This cemented beam splitter provides the greatest angular deviation between the two output beams, and is most commonly used as a polarization analyser. In the first prism both ordinary and extraordinary beams travel collinearly with different refractive indices. At the interface the beams are interchanged, so that the ordinary beam enters a medium of lower refractive index and is refracted away from the normal. The extraordinary beam experiences a higher refractive index and is refracted towards the normal. The divergence angle between them is then further increased at the calcite/air exit surface.

Separation Angle

The deviations of the ordinary and extraordinary beams are nearly symmetrical about the input beam axis, so that the Wollaston polarizing beam splitter has approximately twice the deviation of the Rochon. Standard Wollastons are manufactured with a cut angle of 45°, producing a separation of 20° at 500nm. The separation angle exhibits chromatic dispersion, as shown in the graph. The useful field varies from 22° to 17° over the same spectral range.

Mounts

These polarizers are supplied unmounted as free components unless mounting is specified at the time of ordering. The mount design is in the form of a simple tube with silicone rubber, giving access to the input and output beams. To specify mounted polarizers, simply add suffix: